Refrigerating apparatus



July 18, 1939. J. A. CONRADY 2,166,677

REFRIQERATING APPARATUS Filed March 10, 1937 I NV E NTOR.

1/0 A. Carve/20K RIG-Z I BY q 2 ATTORNEYS.

Patented July18,1939 p UNITED STATESHPATENT OFFICE REFRIGERATING APPARATUS John A. Conrady, Cincinnati, Ohio, assignor to I The Crosley Corporation, Cincinnati, Ohio, a corporation of Ohio Application March 10,1931, Serial No. 130,131

' Claims. ((162-118) My invention relates Specifically to the gention and arrangement of parts which will be deerator absorber in refrigerating apparatus of scribed are accomplished in the-apparatus illusthe intermittent absorption type. trated.

In refrigerating apparatus operative on the Figure 1 is a diagrammatic sectional view of 5 intermittent absorption principle, a refrigerant the refrigerating apparatus illustrating-my in- 5 such as ammonia is employed and an absorbent vention.

such as water. The strong liquor or concen- Fig. 2 is a sectional view along the lines 2-2 trated solution of ammonia in the water is boiled of Fig. 1'.

in a vessel commonly called a generator. This Fig. 3 is a section along line 3-3 of Fig. 1. same vessel usually functions as an absorber. The generator absorber is illustrated at I. At 10 Heat is applied during the heating cycle to cause one end of the generator absorber, there is a the boiling off of the refrigerant. The refrigdome 2 containing the usual rectifying apparatus. erant, in gaseous form, passes under pressure to A tube 3 permits the gasified ammonia and liquor a condensor and receiver in which the gaseous entrainedi therewith to pass into the drum 4. l6 refrigerant is condensed to a liquid and, pend- From the drum 4, a tube 5 provides an outlet for ing its use during the evaporation cycle, stored. the evaporated gases which pass upwardly Toward the end of the heating cycle the liquefied through the entrained liquor trapped in the dome. refrigerant is transferred from the receiver to the An overflow l drains the dome 2 after the eninner shell of the evaporator in which the ex.- trained liquor has filled up the dome to the level 90 pansion of the refrigerant to gaseous condition of the top of the tube 1. The. overflow through takes up heat which, induces such cooling as is the tube 1 drains back into the still absorbent. required for freezing ice cubes and generally I The apparatus also acts as a separator for the cooling the cooling chambersof the refrigerator. gasifled refrigerant.

In some apparatus of the intermittent absorp- From the top of the dome 2, a tube 8 passes g5 tiontype the receiver acts also as the evaporator, to the condenser, coil 9 which is shown as arbut in the particular combination with which ranged in a tank It), cooled with some cooling. I shall describe my invention, the receiver is a liquid such as water. vessel separate from the evaporator. A tube H is connected to the discharge or It is an object of my invention to provide ap outlet from the condenser coil 9 and this drains l0 paratus and a method for setting up a secondary the condensed fluid into the receiver l2.

' circulation of water or other cooling liquid In the receiver l2 there is a return bent tube through coils in the generator absorber which I3 through 'which the condensed refrigerant reduces the temperature of the weak liquor and passes to the. evaporator l4. q t y the P u of the gaseous refris- To prevent the liquor being forced by pressurev 85 era-Ht Within y from the sump [5 into the'vaporator I4, I have 5 It is a further object of my invention to conprovided a'pressure relief tube It having an inlet 'trol the circulation of the cooling water in the H at the top of the tube. Pressure is equalized generator absorber so that it automatically funcbetween the receiver l2 and the evaporator I4 tions at the close of a generating cycle. a by means of the tube I6 until the level of con- 40 A still further object of my invention, in con .densed refrigerant, indicated in dotted lines in 40 nection with the cooling of the weak liquor in Fig. 1, has reached the inlet I! to the tube IS. the generator absorber because "of its effect on -Then when the inlet ll of the tube l6is sealed, the pressure within the system, is to reduce the the liquor is forced by the'pressure in the receiver temperature of the weak liquor so that it becomes l2 into the evaporator l4.- i more effective, in its absorbing properties. After the receiver l2 has been filled to the level v45 Another object is the construction of a 'genof the inlet H and has started to syphon into erator absorber of a novel type which permits the evaporator, the syphoning action continues great efficiency when heat is applied thereto and until substantially all the condensed refrigerant which also permits the positioning of coilstherein' the receiver I2 has 'syphoned over into" the in which are adequately responsive to the estabevaporator. v

lishment 'of thermo syphon cooling systems in The evaporator M has a false bottom l8 havthe water coils in the generator absorber as ining a sum}: [9 at a low point therein. The small duced by a thermostatic control. opening 20 permits the condensed liquid to feed The above objects and other objects relating either in a very fine string or drop by drop into to such novel features as exist in the constructhe evaporating chamber 2| which is formed by 55 Q the space in the evaporator l4 below the false entrainment of unevaporated refrigerant through the pipe 23 into the dome 24, but such unevaporated refrigerant will fill in the dome 24 to the level of the top of the tube 25 and as soon as any additional refrigerant is entrained, it will be returned to the weak liquor in the generator I.

A pressure equalizing tube 26 connects the dome 24 with thedome 2. This prevents the building up of too much pressure on the pressure side of the system.

The ice-cube chamber, as indicated at 21, is

formed by a rectangular shell which is set into of the compartment 28 and acts as an eifective ice cubes during heating cycle.

the end walls of thecompartment 28, the end joints being preferably formed by a welding operation.

The compartment 28 is secured to the evaporator l4 so that the walls thereof are welded to the evaporator in substantially the position illustrated in Fig. 3. Consequently the lower half of the evaporator I4 is set into the top wall of the compartment 28.

Within the compartment 28 a secondary refrigerating system is set up. A preferred refriger-. ant is sulphur dioxide. During the generating cycle, the evaporator |4 becomes warm. The lower wall, were it not for the presence of the sulphur dioxide, instead of a common brine solution such as calcium chloride andwater, etc rapidly exchanges its heat to. the walls of the cooling compartment 21. As the sulphur dioxide gas is warmed up, the warm gas rises to the top insulator, and an'atmosphere of cool sulphur dioxide liquid remains in the lower portion of the compartment 28 which prevents heat being transferred from the evaporator to the SO: brine and in so doing helps to prevent the melting of During the evaporating cycle, the condensed refrigerant, ammonia, drips through the small opening 20 and evaporates in the chamber. This action chills the lower wall of the evaporator. The sulphur dioxide coming into contact with the chilled lower wall of the evaporator will be condensed into liquid form and drip down and strike the liquid above the top wall of the chamber 21. The liquefied sulphur dioxide spread out in a thin film, will begin to evaporate thereby taking heat from the walls of the chamber 21. This will start a circulation of the cold gasses downward and the hot gasses will pass up in the direction of. the arrows illustrated.

It may be that the exact action which I have described will not occur. In any event, the chilled bottom wall of the evaporator M will cause a circulation of the sulphur dioxide gas, the cold gas passing down and striking the top wall of the chamber 21 and the warm gas passing up along the 'outer walls of the chamber 28.

So far the description of my'invention coincides with that of my co-pending application Ser. No. 130,136, filed March 10, 1937. This application involves particularly the specific construction of the generator absorber and the thermo syphon automatically controlled water coil system for cooling the generator.

The generator absorber I is provided with a series of fire tubes 28 through which the hot gasses pass from the fuel burner 3|! which, as

illustrated, may be an oil burner with a fuel such as kerosene. With such a system the quantity of kerosene or other fuel oil received within the well of the burner may be such that a complete generating cycle will be induced before the liquid fuel is consumed. Thus by filling the well in the burner, lighting the wick and permitting all the fuel to burn out, suflicient refrigerant will be evaporated to run the system for 24 hours, or shorter length of time. Regulation of the amount of heat applied will in this way be semiautomatic because only enough fuel will be supplied to complete the generating cycle.

Arranged within the generator I are two sets of coils 3|, 32. The inlet to these coils is at the bottom where elbows 33 and short nipples, not illustrated, extend into a cross, not illustrated, to which the pipe 34 is connected. This manner of connecting two pipes into one is so well known in pipe fitting practice, as what require further coil 38 is from the pipe 35 which connects the out lets at the tops of the two coils 3|, 32.

In the pipe,33, I have arranged a valve 38 which is openedand closed by means of the action of the bellows 38. The bellows are filled with liquid or gas supplied througha pipe "from the'small tank.

The operation of the thermo syphon cooling system for the generator absorber will be obvious from the description of the apparatus. During the interval when the fuel burner is in operation the liquid or gas in the small tank 4| will expand and create pressure in the pipe 48 which will expand the bellows 38 and close the valve 38, so

' that no water can flow through the pipe 33 into the bottom inlets of the two coils 3|, 32. As soon as the fuel is exhausted in the fuel burner or controlled in such a way as to be shut oil, the liquid or gas in the small tank 4| will cool and induce the contraction of the bellows 38 which Thus a thermo syphon water cooling 1. In refrigeratingapparatus of the intermittent absorption type having a refrigerant con tent absorption type having a refrigerant condenser and cooling means therefor, a generator absorber having water circulation coils therein,

a supply of cooling water arranged to be cooled by the cooling means for the condenser, and means for intermittently inducing thermo syphon circulation or water from said cooling water supply through said water circulating coils and a thermostatic control for cutting off said water circulation during periods of generation in said generator absorber.

3. In refrigerating apparatus of the intermittent absorption type having a refrigerant condenser and cooling means therefor, a generator absorber having water circulation coils therein, a supply of cooling water arranged to be cooled by the cooling means for the condenser, and

means for intermittently inducing thermo syphon circulation of water from said cooling water sup- 20 ply through said water circulating coils and a thermostatic control for cutting off said water circulation during periods of generation in said generator absorber, said thermostatic control effective for inhibiting the thermostatic cut off at the end of a generating period.

4. In refrigerating apparatus of the intermittent absorption type a generator absorber, a plurality of coils having inlets at the bottom of said generator absorber and outletssat the top thereof, and means for setting up a thermo syphon system of cool water circulation through said coils.

5. In refrigerating apparatus of the intermittent absorption type a generator absorber, a plurality of coils having inlets at the bottom of said generator absorber and outlets at the top thereof, and means for setting up a thermo syphon system of cool water circulation through said coils and thermal means effective during generation periods in said apparatus for cutting "of! the circulation of water through said coils.

orm a. CONRADY. 

